Downwind Residues from Spraying a Semi-dwarf Apple Orchard

Abstract

Airborne spray and ground deposits were measured downwind from a row of semi-dwarf apple trees sprayed with an orchard air sprayer. Airborne spray collectors used were: string, plastic tape, bottles, and high-volume air-sampler filters; collector locations were at 7.5 to 240 m from the tree row, 0.5- to 10-m elevation. Ground deposits were collected on lines perpendicular to the tree row and at distances from 3 to 240 m downwind from the tree row. A mixture of water and a fluorescent tracer was sprayed on the trees at 468 L/ha during a total of 16 passes on four days and climatological data were recorded.